Having found the pictures this should give you an idea as to how I swapped from a Windscreen mount to a very secure and stable dash vent mount using Brodit/ Pro-Clip parts along with bits from the mount supplied with the Go-1000/ 2505.
First of all I have screwed the Brodit "Ball" part number 533091 to a Pro-Clip to suit my car:
Remove the two Torx head screws in the rear of the mounting shoe
Apply pressure to the joint between the two parts of the shoe using your thumb nail to spring the two halves apart
The front face of the mounting show can now be removed along with the magnet
Next release the four cross head/ Phillips head screws to release the rear of the shoe from the windscreen sucker.
Remove the plastic translucent ball cup from around the ball, it should simply pull out.
Pull the retaining collar from the ball, this takes a bit of force but not too much as there is nothing actually securing it other than being a tight fit.
Now we switch attention to the Pro-Clip and ball, fitting the collar and translucent cap in to place.
Firstly the collar is pushed over the ball.
Next fit the translucent cap
Make sure this is fully seated as there is only one position this can be placed into, a small hole lets a small part of black plastic protrude through the cap at the 12 o'clock and six o'clock positions as shown.
Re-fit the shoe to the collar by securing the four Phillips head screws, its not a bad idea to secure these screws with thread lock to stop them working loose, the screws need to be secure as these provide the friction to prevent the mount from moving under gravity when driving (Droopy mount if screws aren't tight)
Pop the magnet back into position in the slot on the front portion of the mounting shoe.
Snap the front portion of the mounting shoe back in to place and resecure the two Torx head screws in the rear of the mounting shoe.
The modified mount in the car, note the power cable dives through the airvent to a ciggy lighter socket hidden behind the dash providing for a no wires, neat installation.
Finally the unit sat in place:
Hope that helps - Mike